I was very surprised to see the differences in color of registered daylilies shown in the database when I first got into daylilies. I have learned, some cameras do capture different colors differently than others, also having the wrong settings in the cameras are accountable for many of the differences... you can often see that with the blue foliage in the background. This shows up a lot on flowers that claim to be blue.
The lighting at different times of day is a major causes of the different color looks, even an hour can make a big difference. Recently I have noticed that the flower color seems to often be more faded and less vibrant late in the season compared to the bright colors of early spring.